A magical battery I have never seen before

[gamalot]

The output voltage is actually negative 0.27V !!! 

[sarepairman2]

i went back in time and had a word with ben franklin

[gamalot]

I have tested 6x GP Ultra AA size alkaline batteries which worked in my son's toy truck in series,

and their results are : 1.41V, 0.94V, 1.33V, -0.27V, 1.41V. 0.92V

so I'm very curious about why their consistency is so poor 

Hope you guys could understand my English ...

[Muttley Snickers]

Your display on the 1253B is missing bits I noticed....

[gamalot]

Your display on the 1253B is missing bits I noticed....

yes, the refresh rate is too slow I think 

[rickselectricalprojects]

With the batteriser you could...

[PA0PBZ]

I have tested 6x GP Ultra AA size alkaline batteries which worked in my son's toy truck in series,

and their results are : 1.41V, 0.94V, 1.33V, -0.27V, 1.41V. 0.92V

The logical explanation is that the one now showing a negative voltage was inserted the wrong way around.

[Maxlor]

so I'm very curious about why their consistency is so poor 

I'm guessing they were at an uneven state of charge when they were put into the truck. I've seen it too, when the battery is empty yet remains in circuit, current is still being pushed through it and results in a small negative voltage. A bigger problem is that those batteries are now much more likely to leak.

It happens with NiMH rechargeable cells too, and it's a bit more annoying since they're more expensive.

I guess it's a good idea to stick to the recommendation of only putting batteries in series that have the same capacity and state of charge.

[tszaboo]

It is called cell reversal. It was used in a pack, and it was weaker than the others. As current flown through it, it discharged first, and then the others forced current through it, and killed it.
It is probably toast and should be safely disposed, even though maybe it still has like 50% capacity, but the self discharge could be very high, and it will do this again if you use it in a pack. Might spill, might heat up.

[Ian.M]

It is called cell reversal. It was used in a pack, and it was weaker than the others. As current flown through it, it discharged first, and then the others forced current through it, and killed it.

+1. So far so good.

It is probably toast and should be safely disposed, even though maybe it still has like 50% capacity, but the self discharge could be very high, and it will do this again if you use it in a pack. Might spill, might heat up.

Errr . . . .WTF???   Its *NOT* a rechargable, its just dead like Monty Python's parrot!

@O.P.
The unloaded voltage of an Alkaline cell is an unreliable measure of remaining life.  Try again with 100R across the two that read 1.41V, (or with a dedicated battery tester) and if they read >1.3V keep them for a low drain gadget.  Discard/recycle the rest.

[gamalot]

Hi guys, thanks for all the replies 

I did some homework tonight, and finally I realized that 6 batteries are not connected in series into a pack, they are in 2 groups actually!!!

This will explains the strange results I had got before,

1. The 3 batteries in group one, they have nothing wrong, their test results are 1.41, 1.41, 1.33,

2. The other 3 batteries in group two, one of them had been placed in wrong direction, their test results are 0.94, 0.92, -0.27

btw, I had made another mistake, it isn't a truck, it's a excavator 

[gamalot]

here is the picture 

[tszaboo]

It is called cell reversal. It was used in a pack, and it was weaker than the others. As current flown through it, it discharged first, and then the others forced current through it, and killed it.

+1. So far so good.

It is probably toast and should be safely disposed, even though maybe it still has like 50% capacity, but the self discharge could be very high, and it will do this again if you use it in a pack. Might spill, might heat up.

Errr . . . .WTF???   Its *NOT* a rechargable, its just dead like Monty Python's parrot!

@O.P.
The unloaded voltage of an Alkaline cell is an unreliable measure of remaining life.  Try again with 100R across the two that read 1.41V, (or with a dedicated battery tester) and if they read >1.3V keep them for a low drain gadget.  Discard/recycle the rest.

Ah, it is a primary battery? Wasn't clear from the discussion.

[Ian.M]

Errr . . . .WTF???   Its *NOT* a rechargable, its just dead like Monty Python's parrot!

Ah, it is a primary battery? Wasn't clear from the discussion.

Your definition of 'not clear' must be rather strange:

I have tested 6x GP Ultra AA size alkaline batteries which worked in my son's toy truck in series,

Although Rechargeable Alkaline cells exist, the GP Ultra is not one of them.  In fact all of GP's rechargable range use NiMH chemistry.

[tszaboo]

Errr . . . .WTF???   Its *NOT* a rechargable, its just dead like Monty Python's parrot!

Ah, it is a primary battery? Wasn't clear from the discussion.

Your definition of 'not clear' must be rather strange:

I have tested 6x GP Ultra AA size alkaline batteries which worked in my son's toy truck in series,

Although Rechargeable Alkaline cells exist, the GP Ultra is not one of them.  In fact all of GP's rechargable range use NiMH chemistry.

Meh. Maybe I've only read the original post. Happens.

[crispy_tofu]

With the batteriser you could...

800%... less?

Internal electrolyte leaked, causing battery anode tip (or lest lead) to form a primary battery that is negative voltage.

There was a forum challenge thread on this topic, I can not find it anymore.

Was it this one? https://www.eevblog.com/forum/projects/got-2-5v-out-of-a-aaa-battery-no-batteri*er-involved/10/

[gamalot]

Was it this one?
https://www.eevblog.com/forum/projects/got-2-5v-out-of-a-aaa-battery-no-batteri*er-involved/10/

Yes.

thank you very much 

[gamalot]

Was it this one?
https://www.eevblog.com/forum/projects/got-2-5v-out-of-a-aaa-battery-no-batteri*er-involved/10/

Yes.

hi, I am from BIG city Tieling, nice to meet you